Right winger Tom Brennan had a seven-year professional hockey career, which included shorts stints in the NHL with the Boston Bruins over a two-year period.
At the age of 15, Brennan moved to Canada to enhance his playing abilities, and joined the Montreal Victorias where he played for two years. At 17 he played a year with the Montreal Westmount of the MCHL before going to the Montreal Junior Canadiens of the QJHL and finally the Montreal Sr. Canadiens of the QSHL in 1941-42.
Brennan returned to his native Philadelphia at the age of 20 to play for the EAHL's Falcons where he scored 34 goals and 68 points. The Boston Bruins signed him to a contract the following year and he played in eleven games, scoring twice and assisting on one other. In 1944-45, Brennan returned to the EAHL as a member of the Boston Olympics. In 48 games he scored 53 goals and 108 points to lead the league in scoring, winning the John Carlin Trophy. He also played his last NHL game with the Bruins that year. He missed the entire 1945-46 season recovering from back surgery.
Brennan continued to play hockey for another seven years in the Quebec Senior League and the Maritime Senior League, retiring after the 1952-53 season as a member of the Ste. Therese Titans.